P0733
Gear 3 Incorrect Ratio
When a vehicle powertrain module registers the fault code P0733, it points directly to an internal system malfunction identified as "Gear 3 Incorrect Ratio". Operating your engine under this condition may degrade long-term fuel maps.
Driver's Summary
P0733 is triggered when the PCM detects an abnormal condition associated with gear 3 incorrect ratio. Typical symptoms include engine rpms flare up during 2-3 shift, loss of power at cruising speed. Stop driving as soon as it is safe to do so. This fault can lead to expensive secondary damage if left unaddressed.
Symptoms
Engine RPMs flare up during 2-3 shift, loss of power at cruising speed
Common Causes
- Low transmission fluid pressure
- Faulty 3rd gear shift solenoid
- Burned 3rd gear clutch pack
- Leaking internal seals
How to Fix
- 1 Test transmission line pressure
- 2 Replace shift solenoid
- 3 Rebuild transmission to replace clutches and seals
Technical Explanation
Code P0733 is confirmed when the ECM's diagnostic algorithm detects a parameter deviation that persists across a defined number of consecutive drive cycles. The TCM also cross-references engine torque demand, throttle position, and vehicle speed to determine whether the actual gear ratio deviation is genuinely abnormal or a result of expected torque converter slip during aggressive acceleration. The fault remains stored in memory even after the MIL is cleared; it becomes a confirmed DTC after failing two consecutive drive cycles, and the PCM logs a freeze frame record of the engine's exact operating state at the moment of detection.
Is It Safe to Drive?
An active P0733 code under high-severity conditions means the affected system is operating outside safe parameters. Continued driving — especially under load or at highway speeds — significantly increases the risk of secondary damage to components like faulty 3rd gear shift solenoid.
Mechanic's Pro Tip
For P0733, test the solenoid's coil resistance with a multimeter before ordering parts — most solenoids should read between 14 and 40 ohms; an open (infinite resistance) or short (near zero) confirms it's failed electrically. Also verify the PCM is commanding the solenoid by backprobing the connector with a test light during the relevant operating condition — if there's no command signal, the fault is in the PCM or wiring, not the solenoid itself.
Diagnostics/Solenoid: $200 - $600; Transmission rebuild: $2,500+